(1) Field of the Invention
This invention relates to slide valves, and is directed more particularly to a slide valve of the type used for fluid communication between an impulse tank and a launch tube in an underwater vehicle, such as a submarine.
(2) Description of the Prior Art
It is known to use an impulse storage and transfer system in a submarine for ejection of devices from the submarine through launch tubes. In U.S. Pat. No. 4,848,210, issued Jul. 18, 1989 to Laurent C. Bissonnette, there is shown and described an impulse energy storage system having as a principal component thereof an elastomeric energy storage device. The elastomeric device is adapted to accept and store a working fluid such as seawater. In accepting the working fluid, the elastomeric means, a bladder-type accumulator, becomes distended. The accumulator typically is fixed to a slide valve assembly including (1) an impulse tank in fluid communication with the accumulator (2) a launch tube adapted to be in fluid flow communication with the impulse tank, and (3) a slide valve adapted to open and close fluid communication between the impulse tank and the launch tube.
Elastomeric ejection systems are being developed for the quiet ejection of torpedoes, mines or missiles, and such a system is inexpensive relative to existing ram pump and turbine pump types of weapon ejection systems.
Elastomeric launch systems operate in a generally satisfactory manner; however, at the end of the contraction of the accumulator, a noise is generated by the accumulator collapsing upon itself. In U.S. Pat. No. 5,200,572, issued Apr. 6, 1993, in the name of Laurent C. Bissonnette, et al., there is shown and described a configuration of elastomeric accumulator which eliminates or greatly reduces the operating noise of the accumulator.
While such systems therefore radiate relatively little noise upon launch of a weapon, another radiated noise source is present in these prior art systems. Upon weapon launch, a slide valve opens allowing a fluid, such as sea water, to flow quickly into the launch tube from the impulse tank. This sudden rush of fluid often causes a waterhammer and its associated noise in the launch tube.
In the continuing effort to reduce or eliminate noise associated with submarine weapon launches, there is a need for a slide valve which does not cause waterhammer noises during operation.